This invention relates to a fluidized bed reactor and method of operating a fluidized bed reactor and, more particularly, to such a reactor and method in which the reactor is fueled in whole or in part by refuse derived fuel, or RDF.
Cities across the United States and in other countries are seeking alternatives to landfills for the disposal of municipal solid waste, or MSW. Available landfill space is rapidly decreasing, and costs associated with landfill disposal continue to increase. As a result, some cities are turning to incineration as a means of reducing the amount of MSW which otherwise must be sent to landfills while, at the same time, recovering energy from the waste.
In typical waste-to-energy combustors, solid waste is burned on the surface of a grate or hearth, or in a shallow suspension, just above the grate surface. Consecutive agitation of the waste is minimal and is typically aided by mechanical means. Fluidized bed reactors have been proposed for burning MSW and provide a number of advantages over non-fluidized waste reactors. For example, the high turbulence, and therefore intimate mixing of fuel, air, and hot inert particles in a fluidized bed reactor, can provide for combustion efficiencies exceeding 99% as compared to combustion efficiencies of approximately 97% to 98% in non-fluidized waste combustors. Fluidized bed reactors also provide greater fuel flexibility and enhanced pollution control.
However, fluidized bed reactors used to date have not been without problems. For example, to date, fluidized bed reactors have utilized complex combustion systems which include a moving or traveling grate furnace. These systems have many moving parts and typically burn at an elevated furnace temperature that often results in a high furnace corrosion rate, frequent equipment failure, and low plant availability.